Synthesis,separation and structure determination of 2,3,3'‐trichlorobiphenyl (PCB 20)† and 3,3’,4‐trichlorobiphenyl (PCB35)†

The combined synthesis and spectrometric characterization of 2,3,3'‐trichlorobiphenyl (PCB 20) and 3,3’,4‐trichlorobiphenyl (PCB 35) is described for the first time. By a combination of highly efficient column distillation and repeated recrystallizations it was possible to isolate the two products as reference materials with a purity exceeding 99%. X‐ray analysis of crystals of 2,3,3'‐trichlorobiphenyl positively identified the substitution pattern of the biphenyl moiety by chlorine atoms. The two phenyl rings are at an angle of 52°, while the relative disposition of the chlorine atoms on both rings is closer to anti than to syn.     

Optimal Allocation of Conservation Resources to Species That May be Extinct

Abstract: Statements of extinction will always be uncertain because of imperfect detection of species in the wild. Two errors can be made when declaring a species extinct. Extinction can be declared prematurely, with a resulting loss of protection and management intervention. Alternatively, limited conservation resources can be wasted attempting to protect a species that no longer exists. Rather than setting an arbitrary level of certainty at which to declare extinction, we argue that the decision must trade off the expected costs of both errors. Optimal decisions depend on the cost of continued intervention, the probability the species is extant, and the estimated value of management (the benefit of management times the value of the species). We illustrated our approach with three examples: the Dodo (Raphus cucullatus), the Ivory‐billed Woodpecker (U.S. subspecies Campephilus principalis principalis), and the mountain pygmy‐possum (Burramys parvus). The dodo was extremely unlikely to be extant, so managing and monitoring for it today would not be cost‐effective unless the value of management was extremely high. The probability the Ivory‐billed woodpecker is extant depended on whether recent controversial sightings were accepted. Without the recent controversial sightings, it was optimal to declare extinction of the species in 1965 at the latest. Accepting the recent controversial sightings, it was optimal to continue monitoring and managing until 2032 at the latest. The mountain pygmy‐possum is currently extant, with a rapidly declining sighting rate. It was optimal to conduct as many as 66 surveys without sighting before declaring the species extinct. The probability of persistence remained high even after many surveys without sighting because it was difficult to determine whether the species was extinct or undetected. If the value of management is high enough, continued intervention can be cost‐effective even if the species is likely to be extinct.     

Social‐Psychological Principles of Community‐Based Conservation and Conservancy Motivation: Attaining Goals within an Autonomy‐Supportive Environment

Abstract: Community‐based natural resource conservation programs in developing nations face many implementation challenges underpinned by social‐psychological mechanisms. One challenge is garnering local support in an economically and socially sustainable fashion despite economic hardship and historical alienation from local resources. Unfortunately, conservationists' limited understanding of the social‐psychological mechanisms underlying participatory conservation impedes the search for appropriate solutions. We address this issue by revealing key underlying social‐psychological mechanisms of participatory conservation. Different administrative designs create social atmospheres that differentially affect endorsement of conservation goals. Certain forms of endorsement may be less effective motivators and less economically and socially sustainable than others. From a literature review we found that conservation initiatives endorsed primarily for nonautonomous instrumental reasons, such as to avoid economic fines or to secure economic rewards, are less motivating than those endorsed for autonomous reasons, such as for the opportunity for personal expression and growth. We suggest that successful participatory programs promote autonomous endorsement of conservation through an administrative framework of autonomy support—free and open democratic participation in management, substantive recognition and inclusion of local stakeholder identity, and respectful, noncoercive social interaction. This framework of the autonomy‐supportive environment (self‐determination theory) has important implications for future research into program design and incentive‐based conservation and identifies a testable social‐psychological theory of conservancy motivation.     

Demographic Effects of Harvesting Epiphytic Bromeliads and an Alternative Approach to Collection

Abstract: Hundreds of epiphytic bromeliads species are harvested from the wild for trade and for cultural uses, but little is known about the effects of this harvest. We assessed the potential demographic effects of harvesting from the wild on 2 epiphytic bromeliads: Tillandsia macdougallii, an atmospheric bromeliad (adsorbs water and nutrients directly from the atmosphere), and T. violaceae, a tank bromeliad (accumulates water and organic material between its leaves). We also examined an alternative to harvesting bromeliads from trees—the collection of fallen bromeliads from the forest floor. We censused populations of T. macdougallii each year from 2005 to 2010 and of T. violaceae from 2005 to 2008, in Oaxaca, Mexico. We also measured monthly fall rates of bromeliads over 1 year and monitored the survival of fallen bromeliads on the forest floor. The tank bromeliad had significantly higher rates of survival, reproduction, and stochastic population growth rates (λ_s) than the atmospheric bromeliad, but λ_s for both species were <1, which suggests that the populations will decline even without harvest. Elasticity patterns differed between species, but in both, survival of large individuals had high elasticity values. No fallen bromeliads survived more than 1.5 years on the forest floor and the rate of bromeliad fall was comparable to current harvest rates. Low rates of population growth recorded for the species we studied and other epiphytic bromeliads and high elasticity values for the vital rates that were most affected by harvest suggest that commercial harvesting in the wild of these species is not sustainable. We propose the collection of fallen bromeliads as an ecologically and, potentially, economically viable alternative.     

Use of Land Facets to Plan for Climate Change: Conserving the Arenas,Not the Actors

Abstract: Even under the most optimistic scenarios, during the next century human‐caused climate change will threaten many wild populations and species. The most useful conservation response is to enlarge and link protected areas to support range shifts by plants and animals. To prioritize land for reserves and linkages, some scientists attempt to chain together four highly uncertain models (emission scenarios, global air–ocean circulation, regional circulation, and biotic response). This approach has high risk of error propagation and compounding and produces outputs at a coarser scale than conservation decisions. Instead, we advocate identifying land facets—recurring landscape units with uniform topographic and soil attributes—and designing reserves and linkages for diversity and interspersion of these units. This coarse‐filter approach would conserve the arenas of biological activity, rather than the temporary occupants of those arenas. Integrative, context‐sensitive variables, such as insolation and topographic wetness, are useful for defining land facets. Classification procedures such as k‐means or fuzzy clustering are a good way to define land facets because they can analyze millions of pixels and are insensitive to case order. In regions lacking useful soil maps, river systems or riparian plants can indicate important facets. Conservation planners should set higher representation targets for rare and distinctive facets. High interspersion of land facets can promote ecological processes, evolutionary interaction, and range shift. Relevant studies suggest land‐facet diversity is a good surrogate for today's biodiversity, but fails to conserve some species. To minimize such failures, a reserve design based on land facets should complement, rather than replace, other approaches. Designs based on land facets are not biased toward data‐rich areas and can be applied where no maps of land cover exist.     

Multispecies and Multiscale Conservation Planning: Setting Quantitative Targets for Red‐Listed Lichens on Ancient Oaks

Abstract: Species occurrence in a habitat patch depends on local habitat and the amount of that habitat in the wider landscape. We used predictions from empirical landscape studies to set quantitative conservation criteria and targets in a multispecies and multiscale conservation planning effort. We used regression analyses to compare species richness and occurrence of five red‐listed lichens on 50 ancient oaks (Quercus robur; 120–140 cm in diameter) with the density of ancient oaks in circles of varying radius from each individual oak. Species richness and the occurrence of three of the five species were best explained by increasing density of oaks within 0.5 km; one species was best explained by the density of oaks within 2 km, and another was best predicted by the density of oaks within 5 km. The minimum numbers of ancient oaks required for “successful conservation” was defined as the number of oaks required to obtain a predicted local occurrence of 50% for all species included or a predicted local occurrence of 80% for all species included. These numbers of oaks were calculated for two relevant landscape scales (1 km² and 13 km²) that corresponded to various species responses, in such a way that calculations also accounted for local number of oaks. Ten and seven of the 50 ancient oaks surveyed were situated in landscapes that already fulfilled criteria for successful conservation when the 50% and 80% criteria, respectively, were used to define the level of successful conservation. For cost‐efficient conservation, oak stands in the landscapes most suitable for successful conservation should be prioritized for conservation and management (e.g., grazing and planting of new oaks) at the expense of oak stands situated elsewhere.     

Renal tubular dysfunction caused by dietary hexachlorocyclohexane (HCH) isomers

Abstract

Dietary administration of β‐ and α‐hexachlorocyclohexane (HCH) to albino rats caused an abnormal excessive excretion of glucose in the urine, blood glucose level being nearly normal. Occurrence of glucosuria was also accompanied by increased excretions of the two low‐threshold compounds ‐ creatinine and urea, their levels in blood being normal. The interference of HCH isomers with renal function as evidenced by biochemical data was also indicated by histopathological lesions observed in the kidney sections, viz., hypertrophy and degeneration of the renal tubular epithelia.     

Novel synthetic approach to the potent germination stimulant strigol and its analogues

Abstract

Strigol (1) is a natural product that triggers suicidal germination of parasitic Striga species. Here we present an improved annulation sequence for the synthesis of the tricyclic moieties of strigol and its analogues. Our approach makes use of the one‐pot cyclization of 5‐nitro‐2‐pentanone and cyclopent‐2‐enone diesters to afford 7‐methyl‐4‐nitro‐l‐oxo‐hydrindene derivatives. Functional group elaboration of these intermediates leads to a series of hydrindene‐2‐acetic and propionic acids.     

Photomirex: A teratogenicity and tissue distribution study in the rabbit

Abstract

Adult New Zealand white does were intubated orally with single daily doses of 0, 5, or 10 mg of photomirex (8‐monohydromirex) per kg body weight from the 6th through to the 18th day of gestation. Pregnancies were interrupted at term by cesarian section and fetuses removed and evaluated by following routine teratologic methods. Both maternal and fetal tissues were analyzed for residues of photomirex. None of the treated does showed any sign of toxicity. Except for a significant reduction in the mean fetal weight of the 10 mg/kg group all other parameters which evaluated fetal survival and fetal development were within the control range. Photomirex was found in all tissues examined. In the doe, the highest levels were found in fat followed by liver, kidney, spleen, heart, brain and blood. Photomirex was readily transferred across the placenta and accumulated in the fetus. However, in the fetus the highest levels were found in the heart, followed by liver, brain and blood. There were no teratogenic effects at the doses used in this study.